This invention relates to nodes.
Steel node structures are conventionally formed with welded plate node points typically at the intersection of tubular or box members. Cast steel nodes have been developed to improve the performance of such node points in relation to stress flow and fatigue during use.
One object of this invention is to reduce the cost and weight of such nodes by minimising the size of the node and by making savings in pattern making costs. Nodes in accordance with the invention are one piece castings whose stubs are formed onto a central ring or disc.
According to the present invention in one aspect, there is provided a pattern from which a node can be cast as a single integral piece, the pattern being characterised in that it includes a central ring or disc against which one or more stubs abut at selected stations to enable nodes of differing angular geometries and/or stub diameters to be produced from the same pattern.
The axis of the ring or disc is generally, but not always normal to the axes of the main stubs. The ring or disc is preferably of circular form, other configurations may, however, be employed. The presence of the ring or disc also allows the adoption of standardised pattern equipment in which stub pattern pieces may be positioned at selected stations around the circumference of the central ring to allow for differences in stub spacings and angles.